Electrical loud-speaking receiver



July 7, 1925.

H. KOESTER ELECTRICAL LOUD SPEAKING RECEIVER Filed Sept. 23, 1922 I INVENTOR [fir/nan Abasier BY HIS ATTORNEYMLEA Patented July .7, 1925.1

UNITED mm PATENT OFFICE.

HERMAN KOESTER, OF WATER/BURY, CONNECTICUT, ASSIGNOR TO THE BRISTOL COM- PANY, 0F WATERBURY, CONNECTICUT, A CORPORATION OF CONNECTICUT. I

ELECTRICAL LOUD-SPEAKING RECEIVER.

Application fi1etl Septemben23, 1922; Serial No."589,9 79.

To all whom it may concern;

Be it, known that I, HERMAN Kons'rn'n, a citizen of the United States, and a resident of VVat'erbury, in the county ofNew Haven and State of Connecticut, have invented certain new and useful Improvements in Electrical Loud Speaking Receivers, of which the following is a specification. 5

The invention relates to electrical receiver apparatus for amplifying sounds, such. receiver devices being generally termed Loud speaking receivers. The invention relates more particularly to that type of loud speaking "receivers in which there is employed a permanent magnet of such proportions as to carry all the operative parts, and inwhich a one-piece armature lever is provided for actuating the diaphragm, the said lever being suitably fulcrumed to the magnet.

It has located and a more or less balanced armature for this'purpose, and in which the magnetic attraction thereon will not cause an undue tension on the diaphragm. A further object of the invention consists in providing an armature mounting of a minimum num ber-of parts and so arranged as to eliminate friction and the usual adjusting spring.- The novel mounting, moreover, is of such proportions as to suit the desired tension, and will serve'to positively locate the lever with reference to the pole piece of the magnet. Asa result of the improved construction, the diaphragm will be caused to respond more readily and be more sensitive to the fluctuation of current thru vibration' imparted thereby to the lever.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which- Fig. 1 is.a longitudinal section thru the receiver device,

Fig. 2 is a horizontal section taken on the.

line 22, Fig. 1, looking in the direction of the arrows.

' Fi 3 is a transverse-section taken on the line 3'3, Fig. 1, looking in the direction of the arrows and with a portion broken away. a 1

Similar characters of reference designate corresponding parts thruout the several views.

for its object to provide apositively more fully described, .the adjustment being Referring to the drawings, 10 designates a suitable casing or container wherein the entire apparatus may conveniently "be mounted and housed. The device itself comprises a permanent U-shape magnet 11 of substantial proportions and designed to cary the entire apparatus, one leg of said magnet being shorter than the other, the

legs having pole pieces 12 and 13 respectlvely and directed at right angles from the ends thereof. The pole piece 13, further-.

more, is provided with alsdlenoid"14- thru which current passes as received from a transmitting apparatus (not shown), and as is well understood. Suitable leads 15 are connected to the said solenoid for this pur- The magnet 11, in addition, carries a sound box 16 which is adjustably secured thereto for slight angular motion to assist in the tensioning of a lever, hereinafter eli'e'cted, for example, thru nuts 17 work ing on a" screw 18. A nut 19, furthermore,

servesto secure the sound box and attached magnet to the casing 10; and an outlet 2O extends therefrom thru the said casing and may receive a, suitable horn 21 or other amplifying member; y Y

- In order to, effect the amplification, the diaphragm 22 of the sound box is to be vibrated in accordance with the fluctuations of current received from the. transmitting circuit 15, the diaphragm being held securely "in the sound box 16 by rubber washers 23 attraction of the pole piece 13 for its cor-- responding end. The diaphragm end of the lever 24 may be fixedly attached to the diaphragm 22; but it is preferred to provide a loose connection between said diaphragm and lever end, as indicated, and as is more particularly set' forth in my co-pending application Serial No. 569,332.

To aiford a suitable mounting for the armature lever 24 and" which at the same time will provide a force more or 1ess'opposing the magnetic attraction of the po e a fiat strip or piece 25 of spring-metal. To

this end, the strip 25 is arranged to be fastened, as by screws26, to the uprlght portlon or side of the pole piece 12 and itsbifur-' cated end brought over the lever and secured thereto as by screws 27, in manner such that the armature lever, preferably, does not quite touch the top of the pole piece 12; and, of course, to be slightly above the top of the .pole piece 13. The strip 25 is of such resiliency and is'so adjusted that the desired air gap will be maintained between the ar mature lever and pole piece 13 without producing an undue stress on the diaphragm 22, whichis thus in a more or less neutral condition and will most readily respond to the vibrations imparted thereto by the armature lever. An adjustment of the air gap is possible thru the screw 18, as here-inbei'ore set forth. In the use of the aforesaid resilient mounting of the armature lever, furthermore, the usual type of hearing as well as an adjustable tensioning spring are eliminated and the armature lever is positively located with reference to the pole pieces.

I claim V 1. An electrical loud speaking receiver, comprising a permanent magnet having two pole pieces, a diaphragm, an armature lever engaging atone end with the diaphragm,'its other end being under the influence of one of the said pole pieces, asolenoid about the latter pole piece, and a resilient member securing the armature lever to the other of the said pole piecw. 2. An electrical loud speakinglreceiver, comprising a permanent magnet having two pole pieces, a diaphragm carried by the magnet, an armature leverengaging at one I end with the diaphragm, its other end being under the influence of one of the said polepieces, a solenoid about the latter pole piece, and a resilient member securing the armature lever to the other of the said pole pieces.

3. An electrical loud speaking receiver, comprising a permanent magnet havingtwo pole pieces, a diaphragm, an. armature'lever engaging at one end with'the diaphragm, its other end being under the influence of one of the said pole pieces, a solenoid about the latter pole piece, and a flat spring-metalstrip attached to the other of the said pole pieces and to the armature lever.

4. An electrical. loud speaking receiver, comprising a permanent magnet having two pole pieces, a diaphragm, an armature lever engaging at one end with the-diaphragm, its other end being under the influence of one of the said pole pieces, a solenoid about the latter pole piece, a resilient member securing the lever to the other of the said pole pieces, and means to adjust the diaphragm relatively to the armature lever.

5. An electrical loud speaking receiver, comprising a permanent magnet having two .pole pieces, a diaphragm carried by the magnet, an armature lever engaging at one end with the diaphragm, its other end being under the influence'of one of the said pole pieces, a solenoid about the latter pole piece, a fiat spring-metal strip attached to the other of the said pole pieces and to the armature lever, and means. to adjust the diaphragm relatively to the lever.

6. An electrical loud speaking receiver,

comprising a permanent magnet having two pole pieces, a diaphragm, an armature lever engaging at one end with the diaphragm, its other end being under the influence of one of the said pole pieces, asolenoid about the latter pole piece, and a flat spring-metal strip attached to the side of the other of said pole pieces, brought over the said armature lever and attached thereto.

Signed at Waterbury, in the county oi New Haven and State of Connecticut, this 21st day oi? September, A. D. 1922.

HERMAN KOESTEE. 

